1. PHYLUM PORIFERA
Yes! These are animals!!

2. Phylum Porifera 8000 species
Mainly marine but about 100 freshwater species
Sessile adult forms, sometimes benthic
Many different shapes and sizes

3. Physical Characteristics
Body resembles a sac perforated with many holes
PORIFERA = “pore bearer”
Asymmetrical
Sometimes showing irregular shapes
No organs or true tissues present!
Cells show specialization .... different jobs for different kinds!
Cells form layers

4. Body Shape
Simple sponge
Hollow
Upright
Cylindrical

5. Body Shape Complex sponges many shapes Complex body wall …
Inner foldings
Complex systems of canals and chambers

6. So, what are they made of?? Outer layer Inner layer
Thin, flat epidermal cells
Pierced with pores
Inner layer
Specialized cells called collar cells or choanocytes

7. Between the inner and outer cell layers
Jellylike material containing:
Amebocytes – digest food and transport nutrients, as well as secrete skeletal structures
Spicules – the skeletal fibers made from calcium carbonate or silica

8. NO MOUTH!! … how can they eat?!?
Each pore allows water to enter the spogocoel
Sponges can filter food from the water pumped through their pores
(this is why we call them filter-feeders … DUH!!!)
The water then passes out of the osculum, or the opening at the top

9. Water in . . . Water out Water enters through incurrent pores
Collar cells create an inflowing current using their flagella
Water flows through the spongocoel and then the oscula

10. Little Fingers
Food particles are captured and ingested by collar cells lining the spongocoel
Amebocytes in the middle layer pick up partly digested food

11. This gets the point across!

12. Sponge Babies!! Asexual reproduction Sexual reproduction “budding”
Groups of cells divide (“buds”) and break off
Unfavorable conditions lead “buds” to become “gemmules” – buds enclosed by tough outer covering
Sexual reproduction
Collar cells turn into gametes
Sponges are HERMAPHRODITES!!
Sperm leave through osculum and are drawn in through pores in neighboring sponges
Zygote becomes a free-swimming larva and leaves the mother sponge through the osculum

13. It doesn’t look much like a sponge . . . YET!!
Gemmules
It doesn’t look much like a sponge YET!!

14. But, what should I know about Poriferans …
They are the lest complex animals
Simple, simple, simple!!!
They do not show a tissue / organ level of organization
They are filter – feeders
They are BOTH asexual and sexual reproducers

15. THE END!!! You know that I couldn’t leave out this guy . . .
“Everyone’s favorite poriferan!!”